The Forgotten: Welfare Issues of Day-Old Male Chicks

In the egg-producing industry of Flanders, around 24 million male chicks are gassed shortly after birth. This fate is due to their inability to lay eggs and hence, their economic redundancy.[1]

Welfare Concerns During Sexing

Even in the brief span of their lives, these chicks face several welfare issues. The first day, which they spend in the hatchery, is filled with stress due to changes in temperature, noise, handling by staff for sexing, and being crowded on a conveyor belt with a multitude of other chicks. [2] Manual sexing can cause stress and potential injuries. Moreover, the rapid movement of the conveyor belts in the hatchery, coupled with falls from heights between 7 cm to 55 cm during transfers, add to their distress.[3] In addition, chicks frequently tumble off these conveyor belts.[4]

Chicks on a conveyer belt [5]

Welfare Concerns During Gassing

One-day-old male chicks are subjected to carbon dioxide gassing, which leads to suffocation. This process impacts their welfare, causing pain, fear, and respiratory distress before their death.[6] In poultry, exposure to CO2 results in mucous membrane irritation, burning eyes, and a sensation of suffocation.[7]

Ineffective Legislation

Although the Flemish Animal Welfare Code imposes a ban on killing one-day-old chicks bred for egg production, it stipulates that this ban will only be enforced in the future when the Flemish Government determines the feasibility of sexing chicks in the egg by the 12th day after incubation.

The Explanatory Memorandum suggests reasons why ending the killing of one-day-old chicks is currently impossible:

‘At present, four techniques can identify the sex of eggs in ovo. These include DNA analysis, hormonal determinations with and without the use of mass spectrometry, near-infrared spectroscopy, and one based on genetic manipulation.

However, these systems have significant shortcomings preventing their widespread adoption. For instance, they cannot be applied to all eggs, and a substantial proportion of eggs yield no results or unclear ones. Additionally, most techniques have a lengthy analysis time, ranging from 20 minutes to an hour before results are obtained. Some techniques only work at a relatively late stage in the incubation process, and it is preferable to be able to do this at an earlier stage. Lastly, the economic feasibility currently hinders the widespread adoption of these systems.’

Yet, there is strong skepticism regarding the accuracy of these reasons.

Paving the Way to Ban Chick Culling with Advanced Technology: The Respeggt Method and Other Innovations

Despite what the legislative framework might suggest, no significant barriers exist to prevent the widespread adoption of in ovo sexing methods.

The Respeggt method, a refined sex determination technique, is already available and feasible. The procedure includes: [8]

• Verification of fertilization within the egg on the 9th day after incubation.
• Creation of a small aperture in the shell of fertilized eggs using a precision laser.
• Extraction of a small sample of amniotic fluid.
• Testing of this fluid with a marking solution for estrone sulfate, a female hormone indicative of female eggs. If the fluid turns blue, it denotes a female egg. Male eggs are sorted out, preventing their hatching and, thus, the birth of male chicks.

Furthermore, the arguments put forward in Flemish legislation to justify delaying a ban on chick culling can be refuted:

1. The Respeggt sex determination technique is suitable for both white and brown eggs, debunking the argument that the techniques are not applicable to all eggs.
2. The Respeggt method exceeds the desired 98 percent precision in sex determination, refuting the notion of a large proportion of eggs yielding no clear results. PlantEgg also achieves a comparable accuracy[9].
3. The speed of the Respeggt machine is sufficient to handle the sex determination of the 47 million eggs that must be sexed annually in Belgium, negating the argument about lengthy analysis time.[10]
4. Recent scientific research confirms that the Respeggt sex determination technique is safe to apply on day nine, arguing against the assertion that some techniques only work late in the incubation process.[11] Indeed, a recent study commissioned by the German Ministry of Food and Agriculture (BMEL) and carried out by the Technical University of Munich confirms that the physiological neural activity in chick embryos does not begin until the 13th day of incubation. This implies that chick embryos do not process pain prior to this time. [12]
5. The economic feasibility of implementing in ovo sexing is demonstrated by the adoption of the Respeggt method by the Bio-Planet supermarket and the catering company Sodexo,[13] showing that the additional cost is minimal, only an additional 1 to 3 cents.[14]

Given these factors, in ovo sexed eggs can be adopted by other retailers and service providers without practical or feasibility concerns.

Internationally, in-ovo sexing is also considered feasible. In France[15] and Germany [16], a ban on shredding and gassing one-day-old male chicks has been in place since the start of 2022. The killing of chicks intended for the production of consumption eggs should be unequivocally prohibited. The ban can be enforced immediately, as there is no need for a future or delayed ban on chick culling. The Respeggt method already complies with Flemish legislative requirements.

Impact if the Optimal Reality is Realized:

65.000 Animals

65.000 male chicks

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With the implementation of in ovo sexing technologies, such as the Respeggt method, the practice of culling one-day-old chicks could be eliminated. This would prevent the birth of approximately 65,000 male chicks per day in Flanders. Instead of being hatched and then culled, these chicks will not be brought into existence, significantly reducing the number of chicks culled annually.